Thread cutter for looms



June 21, 1955 p, CQNSQLETT] 2,711,193

I TI-READ CUTTER FOR LOOIIS med April 5, 1954 INVENTOR.

65 PAUL C. CONSOLETTI 1 BY ATTORNEY ilnited States Patent THREAD CUTTER FOR LOOMS Eaul C. Consoletti, Milford, Mass, assignor to Draper Corporation, Hopedale, Mass., a corporation of Maine Application April 5, 1954, Serial No. 420,821

8 Claims. (Cl. 139-263) This invention relates to Stafford thread cutters for looms, and particularly to improvements in the blade pivot and lateral pressure means affecting the blade members. It also concerns the mounting for the cutter assembly and the method and means by which the cutter is caused to perform its intended function.

It is a general object of the invention to devise a cutter and clamping means of the class described which shall operate to sever and to retain a thread end with greater efiicacy and which shall be easily and smoothly operated by interconnection to other active loom parts.

It is a further object of the invention to devise a cutter mounting and actuating means which shall provide for universal adjustment of its position and for operation in any of its possible positions without binding and without resort to a great many independent adjustments.

A more specific object is that of pivoting the various blade members so that they are, in effect, axially unrestrained, but float so far as the pivot means itself is concerned, while the lateral pressure between the parts is the result of spring means only which is especially devised for the purpose.

Other objects will become apparent from the following detailed disclosure.

Stafford type thread cutters, so-called, which are actually a combined cutter and thread clamp act at the transfer of a supply of filling to the loom shuttle to enter a shuttle cavity and to sever the outgoing filling so the spent bobbin may be ejected, and to hold the end from the last pick until cut at the cloth selvage and later released at the start of the next following transfer cycle. These cutters and their general mode of operation are well known to those skilled in the art and while they have been used for many years, they are a source of some concern since they must be adjusted rather closely and are subject to rather rapid wear. They must be adjusted for various shuttles, different materials and, if not functioning with reasonable precision, may be the source of serious weaving troubles.

The present invention is directed toward simplification, reduction of size and mass of parts while rendering the adjustments less difiicult. The cutter blades, fixed and movable, are pivoted in a novel manner so that they pivot very freely and are laterally restrained only by the intended lateral pressure developed by springs or the like expressly for the purpose. The blades actually float axially of their pivot except for the lateral pressure imposed upon them and thus with an easy motion for the parts they still sever and clamp with uniform elfectiveness for all materials and over very extended periods of time with little or no attention.

Now the invention will be described in detail by reference to a preferred and other embodiments of the same as illustrated in the accompanying figures of drawing, wherein:

Fig. 1 is a perspective view of a cutter assembly according to the invention.

Fig. 2 is an exploded view of actual cutting and clamping parts.

Patented June 21, 1955 Fig. 3 is a detail view of the blade operating cam.

Fig. 4 is an enlarged view of a novel blade pivot.

Fig. 5 is a detail view of a modified form of blade.

Fig. 6 is a perspective view of an eccentric type of ad justable bracket.

Fig. 7 is a section further showing the mechanism of Fig. 6.

Referring to Fig. 1, the cutter assembly is suspended from a transferred stud 10 or other suitable supporting means. Thebracket 11 has a tongued arm 12 projecting from hub 13 which is clamped by set screws 14 and 15 to the stud, and is engaged by a grooved arm 16 which terminates in a pad 17 formed with slots or other enlarged openings for screws 18 and 19. The two bracket parts may be held clamped in an adjusted position by a screw 20. The tongue and groove may be reversed to opposite parts if desired, but it may be seen that this bracket provides an adjustable support by which the assembly may be angularly varied as to position by swinging it about stud 10 and may be set vertically as screw 20 is loosened, the bracket extended or contracted as need be, and the screw again set up. The slide 21 is in turn movable forward of or back toward the loom lay since it is attached to pad 17 by screws 18 and 19 passing through the aforementioned slots. These also provide a reasonable amount of angular adjustment, it being understood that the cutter normally is set to move at a slight angle to the direction of shuttle motion.

A cutter carrier 22 is slidable in a suitable guideway in the slide 21 and is extended laterally in arm 23 to a blade holder 24. The slide is slotted at 25 to permit the movement of an operating arm 26 which is adjustably held at one end in carrier 22 and at its other end is en,-

gaged by a link 27 of the type which is universally mov-' able through a considerable angular extent. The other.

end of the link is likewise connected by the adapter 28 to a latch depressor stud which, at transfer, imparts the intended cutting motion to the parts.

The cutter and clamp members are illustrated in Figs. 1 and 2 and comprise a fixed member or blade 29 and several movable members. The blade 29 is held in a groove in holder 24 and is retained therein by screw 30.

The blade is apertured at 31, this opening being circular with rectangular extensions as shown for a purpose to be described. The blade assembly further includes a cutter 32 cooperating with the angularly disposed cutting portion 33 of the fixed blade. A shoulder 34 terminates the limit of the thread receiving opening between the blades.

At the opposite side of blade 29 there is provided a fiber clamping member 35 and actuating and clamp arms 36 and 37, respectively. A spring 38 serves 'to induce the required clamping pressure.

The entire movable group are threaded onto the flat sided end members 39 and 40 of pivot 41 which has a central bearing part 42' which is freely rotatable within aperture 31. This pivot is shown to larger scale in Fig. 4. It is drilled and threaded centrally for reception of screw 43 which clamps movable cutter blade 32 onto and 39 of the pivot. A washer, preferably of Belleville type is inserted between the head of screw 43 and the blade so it will be drawn up squarely against the face of the circular central bearing portion 42 of the pivot. The blade is provided with a rectangular opening 44 which may be freely threaded onto the end 39 of the pivot, but which prevents relative rotary motion between the two.

The fiber clamp 35 and arms 36 and 37 are threaded onto the opposite flat sided portion 40 of the pivot. The central part 42 is of slightly less length than the thickness of blade 29 so that blade members 35 and 37 are axially free when nut 45 is tightened on the bolt 43.

1 Spring 38 has an inturned end 46 which enters indentation 47 in arm 36 so that as the arm is moved the spring moves with it. The spring forces the blades 37 and against the fixed blade 29 'to develop clamping pressure as the blades are closed.

Both blade 35 and arm 36 are provided with rectangular openings 35 and 36' similar to that at 44 and these assure that the movement of arm 36 as hereinafter described, will correspondingly move blades 35, 37 and 32.

In assembling these parts, the blade 32. is placed on end 39 of the pivot and with washer W on bolt 43 the latter is threaded into the pivot and tightened. That clamps the cutter blade in place. It is to be understood that this blade is bent slightly so it will have shearing contact with the cutting end 33 of blade 29. By aligning end of the pivot so it will enter the aperture 31 the pivot may be seated in its bearing and locked by rotating about 90. The blades 35 and 3'7 are threaded onto end 40 and with spring 33 on bolt 43, nut 45 is tightened until the assembly is tight against pivot end 40 in whichcondi- 4.

tion the blades will be spring pressed against the central or fixed blade 29, but will be free insofar as axial movement at the pivot is concerned since the space between end extensions'39 and 40 is greater than the thickness of blade 29 and extension 40 is longer than the combined thickness of blade 35 and arm 36 even when blade 32 is not quite in contact with the fixed blade at the pivot.

As the cutter is moved to and fro by link 27, etc., the movable blade members are actuated by contact of a pin 48 fixed in the end of arm 36, with a cam 49, Figs. 1 and 3. This cam 49 is set in a spindle 50 rotatable in a bearing in the boss 51 cast as an integral part of slide 21. Pins 52 and 53 limit swinging movement of the cam and a coil or other spring 54 passed about spindle 50 and fixed to the cam at one end and the pin 52 at the other end is under such tension as to maintain the cam in its inclined (full line) position except as will presently be explained.

In operation of the cutter at transfer it is moved rearwardly by link 27, etc., moving carrier 22 in slide 21. The cutter and clamping blades which are held in closed position since the previous transfer, are opened as the pin 48 passes under cam 49. The pivot point is such that the cam swivels or tilts after pin 48 has been moved down to a position at which the blades open fully. After the pin passes the end of cam 49, the latter then springs to its inclined position and, as a bumper screw 55 or other abutment engages the lay, the carrier 22 is moved reversely or to the front of the loom. As it does so pin 48 rides up cam 49 to close the blades thereby cutting the thread or filling and clamping the end thereof extending to the fabric. The mechanism is so set that at its full rearward movement its blades pass the filling at the shutthe and then as lay, shuttle and cutter move forwardly the closing movement is effected with the thread between 7 the blades. The cam again swivels when pin 48 is raised above the pivot and when the extreme forward position of parts is reached, it clears the cam which under influence of spring 54, moves to inclined position as limited by stop pin 52. The cycle may be repeated at the next transfer.

Abutment screw 55 is threaded into carrier 22 and locked in a properly adjusted position by nut 56.

Referring to Figs. 6 and 7, a modified form of adjustment for the cutter support is shown. A depending bracket has an arm 57 of which a pad similar to pad 17 is a part and a hub 58 slotted at 59. Shaft or stud 10' has clamped thereon by a set screw 60 an eccentric bushing 61. The set screw 60 projects outwardly through slot 59. Hub 58 is clamped to the eccentric bushing by a set screw or set screws 62. Loosening the set screws makes it possible to raise or lower and to adjust the angle of the cutter and, of course, when properly set, the screws are tightened to lock the parts in place. Adjustment forwardly and rearwardly of the loom may still be effected as in the form of bracket described above, Fig. 1.

In some instances, it may be more desirable to actuate.

contact of an abutment or projection of some sort which is a part of the blade arm or arms 36 or 37. In Fig. 5' p a similar member having arms 63 and 64 has a downwardly projecting extension 65 bent as at 66 and threaded to receive an abutment screw 67 adjustably locked in position by a nut 68. The arm 64 instead of having a shouldered pin riveted thereto as above described may have'its end bent laterally as at 69, and preferably, bent at an angle approaching the angle of inclination of cam 49.

The pivot 41 may be a screw machine product, or may be pressed of powdered metal, especially one of selflubricating type. It may be of plastic or formed of metal and precision cast.

The Belleville washer W serves as a means to adjust the shearing pressure at the cutter blades. Normally the 7 axial movement or floating at the pivot permits a sort-of balance to be reached between the shearing and clamping forces or pressures. The washer resilience is resisted by that of the spring 38 and as the washer is drawn up tighter the blade 32 is pressed against the fixed blade with greater lateral force which is resisted by the spring 38.

While one embodiment of the'invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the in vention and the scope of the claims.

I claim:

l. A Stafford type thread cutter and clamp for'loom 9 having in combination, a fixed cutter and clamping blade,

a movable cutter blade anda movable clamping member, pivot means upon which said blades and member are threaded for rotation of the movable blade and clamping member relative to the fixed member while allowing axial floating of the parts, and resilient means for pressing 1at erally against the movable blade and member to bias axially thereon, and resilient means for maintaining lat-:

eral pressure engagement between the said cutting and clamping members.

3. A Stafford type thread cutter and clamp for looms having in combination, a fixed cutting and clamping blade, a movable cutter blade and a movable clamping member,

pivot means comprising a central portion of circular cross section freely rotatable in said fixed blade, said pivot means having end portions of non-"circular section suchj that rotation of the pivot is imparted to both the cutter blade and clamp as the latter are fioatingly mounted axially thereon, and resilient means for maintaiuinglate'ral pressure engagement between the said'cutting and clamping members.

4. A Stafford type thread cutter and clamp for looms having in combination, a fixed cutting and clamping blade,

a movable cutter blade and a movable clamping member,

pivot means comprising a central portion of circular cross section, a generally circular bearing opening in said fixed blade with rectangular extensions within which said pivot is freely rotatable wheninserted therein, said pivot means 7 having end portions of rectangular section of sizeto be insertable through said circular bearing opening and its rectangular extensions, said movable cutter blade and clamping members having cooperating openings for threading over said pivot end portions and to impart rotative movement through the pivot from the clamping members to the movable cutter blade while permitting unrestrained axially directed movement therebetween, and resilient means for maintaining lateral pressure engagement between the movable and fixed cutter blades and between the clamping members and the relatively fixed blade member.

5. A Stafiord type thread cutter and clamp for looms having in combination, a fixed cutting and clamping blade, a movable cutter blade and clamping blade members pivoted to move with said movable cutter blade and having an arm with a cam engaging projection, swivelling cam means for said cam engaging projection, and other means by which said movable blade and clamping members are caused to effect a blade closing movement which comprises a laterally extending arm as a part of said first mentioned arm and an adjustable abutment ried by said laterally extending arm.

6. A Stafford type thread cutter and clamp for looms having in combination a slide, a carrier movable in said slide to which cutting and clamping means are fixed for movement to and from an active or cutting position, a

means carsupport means for said assembly which includes a bracket, said bracket comprising a pad for attachment to said slide, a hub by which the assembly is clamped to a supporting stud, and an extendable arm means interconnecting said pad and hub.

7. Mechanism as defined in claim 6 wherein said pad is adjustably attachable to the slide.

8. Mechanism as defined in claim 6 where said adjustable arm comprises relatively extensible and contractible members one of which is grooved and the other of which has a tongue for reception in said groove, and means for clamping said members in a set position.

References Cited in the file of this patent UNITED STATES PATENTS 1,552,388 Stafiord Sept. 1, 1925 2,446,444 Turner Aug. 3, 1948 2,654,400 Donoghue et al. Oct. 6, 1953 2,665,717 Smith Jan. 12, 1954 

